Human Conditional Reasoning in Answer Set Programming
Chiaki Sakama
TL;DR
This paper addresses realizing human conditional reasoning within Answer Set Programming (ASP) by introducing modular completion mechanisms for four inference patterns: Affirming Antecedent ($AA$), Affirming Consequent ($AC$), Denying Antecedent ($DA$), and Denying Consequent ($DC$). It defines eight completion types (AC, DC, DA and their default variants) and demonstrates their semantics via answer sets, enabling backward and contrapositive inferences in a principled, context-sensitive way. The authors connect these completions to cognitive psychology tasks (e.g., suppression and Wason selection) and show how they can model abductive explanations, counterfactual reasoning, and neighborhood inference for commonsense AI. The approach preserves ASP's declarative nature while providing a modular, syntax-dependent toolkit to realize pragmatic human-like reasoning and to support broader AI applications in commonsense reasoning. Overall, the work bridges cognitive psychology and ASP by offering a flexible framework to simulate context-driven human reasoning within a well-established logical programming paradigm.
Abstract
Given a conditional sentence "P=>Q" (if P then Q) and respective facts, four different types of inferences are observed in human reasoning. Affirming the antecedent (AA) (or modus ponens) reasons Q from P; affirming the consequent (AC) reasons P from Q; denying the antecedent (DA) reasons -Q from -P; and denying the consequent (DC) (or modus tollens) reasons -P from -Q. Among them, AA and DC are logically valid, while AC and DA are logically invalid and often called logical fallacies. Nevertheless, humans often perform AC or DA as pragmatic inference in daily life. In this paper, we realize AC, DA and DC inferences in answer set programming. Eight different types of completion are introduced and their semantics are given by answer sets. We investigate formal properties and characterize human reasoning tasks in cognitive psychology. Those completions are also applied to commonsense reasoning in AI.
